If your opponent Summons a monster on their first turn, this monster could easily be Summoned, and then Tribute it for "Great Maju Garzett", which would have an ATK of 4200.
With three "Proto-Cyber Dragons" on the field, equip this card with "Chthonian Alliance" for a boost of 2400. And with three "Cyber Dragon Zweis" in the grave, equip this card with "Phalanx Pike" for a 2700 boost for a total ATK of 7200. Double its original ATK with "Limiter Removal" for an OTK.
With the release of "Drei" and "Core" this card can gain as much as 5400 additional ATK using "Phalanx Pike" resulting in the ATK of "Cyber Dragon" being as high as 10200 with "Phalanx Pike" alone, easily enough for an OTK.
Your opponent's "Cyber Dragon" can be used to Summon "Chimeratech Fortress Dragon".
Use "DNA Surgery" to pull out "Chimeratech Fortress Dragon" easier while clearing your opponent's field for attacks
Use "Light of Intervention" to prevent your opponent from setting monsters and keeping them face-up to use them as Fusion Materials.
Consider using "Level Eater" on "Cyber Dragon" to gain another 1000 Attack.
Due to its ability to Special Summon itself, "Cyber Dragon" is very good at using Union monsters. Some helpful monsters to connect are "Oilman", for extra draw power, "Trigon", to Summon more monsters (like "Cyber Dragon Zwei"), "Armored Cybern" for "Cyber Dragon" support or "Heavy Mech Support Platform" for extra power to beat monsters like "Stardust Dragon". The layer of destruction defense is helpful, too.